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Freeze-a-like

Started by potul, January 11, 2011, 09:14:48 AM

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potul

This is one of the things I want to try. I've always thad the FFT-IFFT option in my head, and I even tried to simulate it in the PC with some good results. The only drawback I see (without really having tried) is that it requires a big size FFT, and with the dsPIC I'm quite limited in memory, I can't really handle more than 256 points FFT.


add4

I'm quite certain that the FFT or DWT is the way to go for the freeze.. but i'm learning to make analog effect at the moment.. i'd love to build a DSP based effect later, but now that i have finished my thesis, i'm SICK of programming signal processing applications :p
And i have always worked on Matlab, never with DSPs... a lot of things to learn i guess.
Maybe later.
I'd love to hear from anyone who tries this approach


DavenPaget

Hiatus

slacker

You can do a freeze effect using a reverb algorithm using 100% feedback and killing the input. I've done it on the FV-1 and it sounds pretty good.

potul

Quote from: slacker on November 22, 2011, 01:04:18 PM
You can do a freeze effect using a reverb algorithm using 100% feedback and killing the input. I've done it on the FV-1 and it sounds pretty good.

mmm... interesting approach. Is it something similar to a Shimmer?

slacker

Here's an example of using reverb to do a freeze type effect, jump to about 4:10
.

crane

Quote from: slacker on November 22, 2011, 01:04:18 PM
You can do a freeze effect using a reverb algorithm using 100% feedback and killing the input. I've done it on the FV-1 and it sounds pretty good.
+1 from me
I've tried this on a FV-1 demo board - took a while to get into spinasm, but the result was quite good... I think :D
Right now I'm developing a stand alone unit for doing this.
Here's my progress so far:

Let's see how it goes :)
Meanwhile >> HERE << is a link to a sample - it is not musical - sorry for that, but you can get general concept :)

Hides-His-Eyes

Quote from: crane on November 24, 2011, 11:08:42 AM
Quote from: slacker on November 22, 2011, 01:04:18 PM
You can do a freeze effect using a reverb algorithm using 100% feedback and killing the input. I've done it on the FV-1 and it sounds pretty good.
+1 from me
I've tried this on a FV-1 demo board - took a while to get into spinasm, but the result was quite good... I think :D
Right now I'm developing a stand alone unit for doing this.
Here's my progress so far:

Let's see how it goes :)
Meanwhile >> HERE << is a link to a sample - it is not musical - sorry for that, but you can get general concept :)

Very good! Does one of the 'pots' control the hold function?

slacker

#28
Very nice, sounds really good, mine needs some work but it proves the concept works. I guess you're using a switch connected to one of the pot inputs to control it?

If anyone wants to try this on the FV-1 or just get an idea of how it works, then Dave Spinkler's Reverb+HP+LP code here http://www.spinsemi.com/programs.php does infinite reverb, use a switch instead of the reverb pot, add a clean blend and you're good to go, that's what mine is based on/stolen from.

crane

#29
Quote from: Hides-His-Eyes on November 24, 2011, 01:07:33 PM
Very good! Does one of the 'pots' control the hold function?
Yes, one of the FV-1's "pot" controls the hold function - but it I don't think that it is as simple as adding a switch to it. We'll see - I didn't add a switch on my development board, let's see how the real board turns out. I'm missing some components, otherway I would finish it tonight.
A pot in signal line controls level of the hold signal.
Dry signal does not go through FV-1 - it goes through a buffer (this is because a pedal like this cannot be true bypass  - I wanted mine to be at least good buffered bypass, so that the clean signal does not have to go throu ADC/DAC
If it runs out good I might be selling some pcbs.

Scrutinizer

Perhaps this will help: I get a freeze effect with my Axe-FX using delay algorithm that has four delays (the band delay), each with independent feedback path that can be set to 100% feedback.
http://wiki.fractalaudio.com/index.php?title=File:Band_Delay_block.jpg

The delay times are set to four randomly selected values between 100 and 200ms. I've tried this using only one delay line and it does not sound good - the loop point is very obvious. But with four delay lines, the loop point is well hidden.

I have had even better sounding freeze effect by using two of the blocks mentioned above .. for a total of eight delay lines, each with slightly different timing (between 100 and 200ms). This provides a thickly chorused freeze effect.